Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 19-10-2019, 04:45   #1
Registered User

Join Date: Oct 2013
Posts: 152
Winter storage of lifepo4

My boat is hauled out and winterised for the coming cold period. We have like 4 months dec-mar below freezing. I have a 200ah winston lifepo4 pack in the boat. Just checked it and the cells are like 3.27v and soc is 55%. I have turned off the main circuit breakers and switched the load/charging relays off. Only thing that draw some current is the 123bms. Anything else I should do? I rather not take the pack out and haul it home.
__________________

Flod is offline   Reply With Quote
Old 19-10-2019, 06:25   #2
cruiser

Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,304
Re: Winter storage of lifepo4

I would prefer to isolate the cells from BMS, not doing anything while in cold storage anyway.

And do not believe that -45C, make sure the **inside** of the cells are well above freezing before allowing even a 0.05C charge rate.

Just how cold do you expect it to get there?
__________________

john61ct is offline   Reply With Quote
Old 19-10-2019, 12:25   #3
Registered User

Join Date: Oct 2013
Posts: 152
Re: Winter storage of lifepo4

At most -15-20 degrees C. I wont charge or use the batteries in the cold though.
Flod is offline   Reply With Quote
Old 19-10-2019, 13:04   #4
cruiser

Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,304
Re: Winter storage of lifepo4

Should be OK. Maybe I'm ovrly cautious, but IMO if power's available, a low level heat source for peak cold overnights would not be a bad idea.
john61ct is offline   Reply With Quote
Old 24-11-2019, 06:10   #5
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 13,774
Re: Winter storage of lifepo4

This is the exact same situation I would have during the winter when and if I go with lifepo. So I thought, rather than move them home, perhaps use solarpv to warm up a resistance blanket during the day to keep the battery warmer at night and reduce thr low temps a little. The Boatyard allows no connections.

I dont know if it would work. Also if they loose charge, youd best be very careful about temps before charging them back up.

Some blanket insulation will also help to average out the temps
rgleason is offline   Reply With Quote
Old 24-11-2019, 07:34   #6
Registered User

Join Date: Sep 2018
Location: Maryland
Boat: 1985 Ericson 32-3
Posts: 245
Re: Winter storage of lifepo4

I'd increase the charge to 75-80% just in case there is a minor parasitic drain, disconnect the cables (BMS if external), clean the plastic case, and record the SOC once every month or so. It should be fine till Spring.

Obviously warm it to above freezing for more than a few hours if it does need a charge.
Checkswrecks is offline   Reply With Quote
Old 24-11-2019, 08:05   #7
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 13,774
Re: Winter storage of lifepo4

Do lifepo when colder, use up some energy or do they just go into hybernation, with out movement of electrons?

Does anyone have experience with cold conditions and lifpo? How often should they be recharged in the winter?

Getting the boat and batteries up to proper temp in order to charge, might be difficult. What do others do?

Moving the battery might prove to be very disruptive, requiring some dismantling.

Hope you'll share your experience this winter
rgleason is offline   Reply With Quote
Old 24-11-2019, 08:57   #8
cruiser

Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,304
Re: Winter storage of lifepo4

Bare cells isolated have near zero cell discharge, and cold is ideal for long term storage, even years is fine without topping up. BMS or other parasitic loads are the dangerous wild card.

Personally I would check periodically, more frequently at first until confident, then scale back, eventually to say every other month.

A well insulated box with thermostatically controlled silicone heating pads at the bottom is the usual solution when needed.

If an easy water heating system was available then a hydronics solution might be easier.

Yes a long warm-up period is required to ensure the cell interiors match ambient inside the box.

Personally I'd rather design the bank from easily portable units.

There are also systems where the heating elements are part of the battery design.
john61ct is offline   Reply With Quote
Old 04-12-2019, 06:49   #9
Sponsoring Vendor
 
YANDINA's Avatar

Community Sponsor

Join Date: Nov 2019
Location: South Carolina
Boat: Philip Rhodes Custom 71'
Posts: 49
Re: Winter storage of lifepo4

A recent news article describes cryogenic freezing of Lithium batteries in liquid Nitrogen to immobilize them for transportation without the need for expensive protective packaging.

Tests after thawing showed no difference immediately however the ones that had been frozen had longer life.
YANDINA is offline   Reply With Quote
Old 04-12-2019, 10:35   #10
cruiser

Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,304
Re: Winter storage of lifepo4

Very interesting!

In rereading my post above, realized this bit
Quote:
Originally Posted by john61ct View Post
Personally I'd rather design the bank from easily portable units.
may need clarifying.

Point being, just bring the packs inside to store them above ~10C when it gets really freezing in their usual location(s).

In many contexts much more practical than heroic measures creating a dedicated temp-controlled insulated enclosure.
__________________

john61ct is offline   Reply With Quote
Reply

Tags
lifepo4, storage

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sinopoly LiFePO4 instructions for storage. rvlandlubber Electrical: Batteries, Generators & Solar 23 09-11-2018 22:05
WINTER COVERS SPECIAL -> PROTECT YOUR BOAT THIS WINTER Master Lex Vendor Spotlight - Great Deals for CF Members! 18 26-11-2014 04:53
Dingy winter storage turkish6 Auxiliary Equipment & Dinghy 1 11-10-2007 02:51
Winter Storage - Champlain Canada Sarah_Crowhurst Marinas 0 12-09-2007 09:11
Winter Storage in Lake Champlain Sarah_Crowhurst General Sailing Forum 0 03-09-2007 11:43

Advertise Here


All times are GMT -7. The time now is 18:42.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.